Gastrulation Flashcards
What happens in gastrulation?
The bilaminar embryo is transformed into one that has 3 GERM LAYERS: ECTODERM, MESODERM, ENDODERM.
What does the ectoderm give rise to?
Skin and nervous system.
What does Mesoderm give rise to?
Bone, muscles and mesentries.
What does the endoderm give rise to?
The lining of the gut and large glands such as liver and pancreas.
What is the first sign of gastrulation?
The primitive streak.
What role does the notochord play?
Plays an important role in the development of the nervous system, and eventually disappears.
*(It’s the only non-[aired mesodermal structure.)
What do the somites start off as?
Somitomeres which are loosely packed.
What are some structures the somites will form?
- Cartilage of vertebrae and ribs
- Muscles of trunk and limbs
- Tendons that connect muscles and bones
- The dermis of the dorsal skin
- Structures of the circulatory system
What structure will the sclerotome form?
firstly they become mesenchymal»_space; cartilage cells of the vertabrae and a lage part of the ribs»_space; bone.
What structure will the syndetome give rise to?
Tendons that attach to the bone
Myotome cells will give rise to…?
All the skeletal muscles of the body (except head muscles)
Dermatome will give rise to?
They will contribute to connective tissue (dermis) of the dorsal skin.
What will the intermediate mesoderm give rise to?
The urogenital system (kidney, goands and associated ducts).
What does the lateral plate mesoderm split up into?
1) The visceral lateral plate mesoderm
2) Parietal lateral plate mesoderm
What does the visceral lateral plate mesoderm give rise to?
The heart and smooth muscle and connective tissue of the wall of the gut.
What does the parietal lateral plate mesoderm give rise to?
Form the parietal peritoneum, a smooth layer of tissue that lines the inside of the body wall.
- At the level of the limbs, cells of the parietal lateral plate mesoderm proliferate and migrate to form the skeletal structures of the limbs.
What does the ectoderm give rise to?
The skin + nervous system
What does the mesoderm give rise to?
bone _muscle + mesentries
What does the endoderm give rise to?
the lining of the gut + large glands such as liver and pancreas.
What does the first migration involve in gastrulation?
The cells of the epiblast migrate towards the midline and occurs from the caudal end of the epiblast.
What does invagination mean (in regards to gastrulation)?
Downwards towards the epiblast
